某校为了了解初三年级500名学生的课外作业量,从中抽取了50名学生的课外作业进行

题型:填空题

问题:

某校为了了解初三年级500名学生的课外作业量,从中抽取了50名学生的课外作业进行检查,在这个问题中,样本是(    )。

考点:总体、个体、样本、样本容量
题型:填空题

羊水是胎儿在子宫内生活的环境,其体积和化学组成维持在一个动态范围内。早期妊娠的羊水组成类似母体血清的透析液,随着胎儿生长,羊水在多方面发生变化,羊水中出现从羊膜、胎儿皮肤、呼吸道支气管树脱落的细胞,在产前诊断方面有重要用途。

正常足月妊娠时,羊水量约为()

A.600ml

B.700ml

C.800ml

D.900ml

E.1000ml

题型:填空题

请完成函数fun( ),它的功能是:求Fibonacc数列中小于t的最大的一个数,结果由函数 0返回。Fibonacc数列F(n)定义为:
F(0)=0,F(1)=1
F(n)=F(n-1)+F(n-2)
例如:t=1000时,函数为987。
注意:部分源程序给出如下。
请勿改动主函数main和其他函数中的任何内容,仅在下划线上填入所需的内容。
#include<conio.h>
#include<stdio.h>
#include<math.h>
in fun(int t)

int a=l,b=1,c=0,i;
do

1
a=b;
b=C;

while( 2 );
c= 3
return C;

main()

int n;
clrscr();
n=1000;
printf("n=%d,f=%d\n",n,fun(n));

题型:填空题

(12分)化合物YX2、ZX2中,X、Y、Z的核电荷数小于18;X原子最外层的p能级中有一个轨道充填了2个电子,Y原子的最外层中p能级的电子数等于前一层电子总数,且X和Y具有相同的电子层数;Z与X在周期表中位于同一主族。回答下列问题:

(1)Y的价电子轨道表示式为                      

(2)YX2的电子式是               ,分子构型为        ,中心原子发生了____杂化。

(3)Y与Z形成的化合物的分子式是_______,该化合物中化学键是________键(填“极性”或“非极性”),该分子属于__________分子(填“极性”或“非极性”)。

(4)Y的氢化物中分子构型为正四面体的是__     _____(填名称),键角为_______,中心原子的杂化形式为_______。

(5)元素X与Y的电负性的大小关系是___________(用元素符号填写,并填﹥、﹤、﹦),

X与Z的第一电离能的大小关系是___________。(用元素符号填写,并填﹥、﹤、﹦)

题型:填空题

调整后的床鞍与导轨间的间隙,应保持刀架在移动时平稳、灵活,无松动或无阻滞感。( )

题型:填空题

"The imperative to self-knowledge has always been at the heart of philosophical inquiry," wrote MIT professor Sherry Turkle in the insightful book about the web and the self, Life on the Screen: Identity in the Age of the Internet. Published in 1995 as the second part of a trilogy that examined our relationships with technology, it looked at how we are who we are in online spaces. And what that means for us offline.

The good news is that the results are positive: "Play has always been an important aspect of our individual efforts to build identity," she said, referencing developmental psychologist Erik Erikson, and nodding to the theories of psychoanalysts Freud, Lacan and Jung. "In terms of our views of the self," she wrote, "new images of multiplicity, heterogeneity, flexibility, and fragmentation dominate current thinking about human identity. "

At the time Life on the Screen was released, most of the visitors were college students and their professors from a remarkably small talent pool, and a surprisingly small geography. They were tech-savvy, and generically open-minded about the new fields of virtual exploration that lay within the networks of this new communication platform. They were, in other words, liberal, enlightened types who were more willing to embrace the unprecedented fluidity of self-expression that this new technology uniquely afforded.

As a psychoanalyst and a web user herself, Turkle spent much of the book explaining why the articulation of multiple personalities wasn’t pathological. Contrary to its Latin root, identity need not mean "the same", she argued. "No one aspect can be claimed as the absolute, true self", she wrote, maintaining that the web allowed us the opportunity to get to know our "inner diversity". In the great psychoanalytic tradition, she said that self-actualisation meant coming to terms with who we are, and integrating each aspect of it into a coherent and well-integrated us.

Almost everyone has experienced this kind of identity play. Even if you’ve never ventured into an online game or been a signed-up member of a web community, you’ve probably developed a profile for a social network, written a blog, styled a website, commented on an article. But things are different from the time when Turkle was writing Life on the Screen. Nowadays, our virtual social lives are increasingly integrated. with our offline social lives. The freedom of expression is curtailed by the threat of offline consequences from online actions. Today, your reputation offline is far more closely tied to your reputation online than before. In fact, our experience of contemporary identity online is disarmingly similar to offline.

However, I still subscribe to the old Turkle. Consequence-free online environments allow us to practise and play without fear of offline effect, and offer an extraordinary place to experience the fluidity of our selves: I can be anyone, even a dog. As Tom MacMaster found, there still are places online where this is possible.

According to the author, almost everyone has tried to()

A. sign up for an online game with a website

B. change his lifestyle by networking with online visitors

C. associate his online life with his of f line reputation

D. construct an online identity in one way or another

更多题库